1. Field of the Invention
The invention relates to a liquid discharge head, and more particularly to an ink jet recording head for recording by discharging a recording liquid onto a recording medium, and a method for manufacturing the same.
2. Related Background Art
Examples of using a liquid discharge head for discharging a liquid include an ink jet recording system for recording by discharging an ink to a recording medium.
An ink jet recording apparatus used in the ink jet recording system is a recording apparatus of so-called non-impact recording system, and it is capable of recording at high speed and recording on various recording media, while generating almost no noise during recording. A typical example of ink jet recording system is a system using an electrothermal transducing element as discharge energy generating element. In the ink jet recording head of this system, the electrothermal transducing element is provided in a pressurizing compartment, and an electrical pulse is applied to it as recording signal, and thereby a thermal energy is given to the recording liquid. By using the pressure of the bubble at the time of bubbling (boiling) of recording liquid caused by phase changes of recording liquid at this time, the recording liquid is discharged.
FIG. 7 is a sectional view showing an example of mode of mounting a recording element substrate on a support member in the ink jet recording head. As shown in FIG. 7, in a discharge port plate 104 provided at the surface side of a first recording element substrate 103, a plurality of discharge ports 104a for discharging a recording liquid are opened at a position opposite to an energy generating element (for example, electrothermal transducing element) 105. The discharge ports 104a are opened in two rows, and two rows compose one set of discharge port rows. In a support member 101, recording liquid supply paths 101a are disposed as being separated by a partition wall 101b, and the support member 101 is bonded to the recording element substrate 103 at high precision. The adhesive used in bonding is, for example, a thermosetting adhesive which is cured by heat. The support member 101 is often composed of an ordinary resin formed material or a member containing such material, and hence when curing the adhesive, it is desired to be cured at a relatively low temperature. Japanese Patent Application Laid-Open Nos. 2000-80340 and 2000-68294 disclose an electrical insulating adhesive used for mounting an electronic device such as semiconductor chip on a substrate. This adhesive contains an epoxy resin of high reactivity having an epoxy equivalent of 150 or more, and is hence cured at low temperature. In the ink jet recording head manufactured by using the adhesives disclosed in these publications, the ink resistance was tested, and ink staining was grossly observed on the adhesion boundary. The reason is estimated as follows. The ink used in the ink jet recording method often contains alkaline solvent or polar solvent in order to dissolve and stabilize the dye and pigment. In the ink jet recording head using the adhesive cured at low temperature, the uncrosslinked portion not promoted completely in reaction cannot withstand the ink, possibly leading to such problem.